286 DRY FARMING 



the older plains States between Kansas and Western 

 Canada. 



239 A. The Value of Manure. — What has been said 

 about the advantages of organic matter in Chapter III 

 and in other places applies in a greater degree to manure. 

 The value of this fertilizer is not chiefly in the food 



Fig. 95. — Cereal Test Plots at Beaver Lodge, Grande Prairie District, 

 Northern Alberta. 



material it carries but rather in its physical and biol- 

 ogical effects on the soil. It not only adds some elements 

 of plant food but it improves the structure of the soil, 

 increases its moisture-holding power, lessens the tend- 

 ency to blow and, perhaps most important of all, in- 

 creases the activity and the number of the desirable soil 

 bacteria that perform the important function of making 

 plant food available. 



According to Hopkins* "a, ton of fresh-mixed cattle 

 and horse manure contains about 500 pounds of dry 

 matter, 10 pounds of nitrogen, 2 pounds of phosphorus, 

 and 8 pounds of potassium. ... By leaching and fer- 

 mentation the dry matter, nitrogen, and potassium are 

 lost in approximately the same proportion, but the phos- 

 phorus is lost only about half as rapidly, so that one ton 



*In "Soil Fertility and Permanent Agriculture." 



